US2451548A - Swarf milling machine - Google Patents

Description

W. GROEN EI'AL Oct. 19, 1948.

SWARF MILLING MACHINE 4 Sheets-Sheet 1 Filed Sept. 21, 1944 Get 1948- w. GROEN EI'AL 45154 SWARF MILLING MACHINE Filed Sept. 21, 1944 I 4 Sheets-Sheet 2 Oct. 19, 1948. w GRQEN ETAL 2,451,548

SWARF MILLING MACHINE Filed Sept. 21, 1944 4 Sheets-Sheet 3 Oct 19, 1948. w, G OEN ETAL 2,451,548

SWARF MILLING MACHINE Filed Sept. 2l 1944 4 Sheets-Sheet 4 Patented Oct. 19, 1948 NITED STATES PATENT OFFICE SWARF MILLING MACHINE Willem Groen and Rudolph F. onsrud, Chicago, Ill., assignors to Onsrud Machine Works, Inc., Chicago, 111., a corporation of Illinois Application September 21, 1944, Serial No. 555,088

8 Claims.

This invention relates to milling machines for surfacing the faces of long pieces of work, such for example as the main beams of airplane wings to conform them to warped surfaces like those of airfoils.

The specific structure herein shown and described is in the nature of an improvement upon certain features of Patent No. 2,345,494 Spar tapering and shaping machines, issued to Rudolph F. Onsrud March 28, 1944. c

The main objects of thisinvention are to provide improved means for mounting a horizontally journalled cutter; to provide improved means for changing the axial disposition of such cutter both as regards elevation and inclination during its travel along the work-holding bed; and to provide mounting and control means for such devices which shall be sensitive to the influence of the control means but firmly resistant to deviation by resistance of the work to the cutting tool.

A specific embodiment of this invention is illustrated in the accompanying drawings in which:

Figure 1 is an elevation of a swarfing milling machine viewed from the direction of travel of the carriage, with its supporting frame partly broken away and its air and water piping, electric cables and trolley omitted for clearness. v

Fig. 2 is a top plan of the same, with the frame bed partly broken away at both ends.

Fig. 3 is an elevation. viewed from Figs. 1 and 2. f

Fig. 4 is a diagram explanatory of the method the left of of controlling the lifting and tilting movements along the work supporting lbedof the base I'. This machine is particularly, designed for finishing the longitudinal surfaces of structural beams and spars and the bed. is equipped with a multiplicity of transversely disposed work-holding blocks 4 equipped with transverse key slots 5to receive the attaching bolts by means of which the work is secured, as will berun'derstood An elevator i 19??? 5 29 the 9? F? be? plate standing in a vertical plane at the front end of the carriage 2 is carried by two sets of parallel links I of equal length whereby the elevator block 6 may move up and down but is always held in a vertical position. The links I are carried by trunnion shafts 8 mounted in bearings 9 on the carriage 2 and the outer ends of the corresponding horizontal pairs of these links I are connected by trunnion shafts l0 on which the elevator 6 is pivotally hung.

A transversely extending tilting member having a sector portion I l is mounted on an arbor I2 on the block 6 and is slidably held by arcuate guideways i3 and I4 which, in section, are shaped to radially embrace the end edge of the forwardly extending portion l5 and the circular marginal rim of the sector portion I I, respectively.

The forwardly extending portion 15 of the tilting member is also provided with a horizontal guideway I6, on its under face; for a dovetail slide 11 by means of which the frame l8, which carries the motor and cutting tools, is mounted 'to slide horizontally across the bed I for the purpose of bringing the rotary cutters I9 into transverse registry with a piece of work on the bed.

In the form shown, the motor 20 is integral with this frame l8 and its main shaft 2| is the spindle upon which the cutters [9 are mounted. A spherical roller 22 is journaled adjacent the end of the spindle 2! that is at the left of Figure 1 and this roller cooperates with a template bar 23 for tiltingthe cutter spindle angularly about the axis of the arbor l2 of the tilting sector. The roller 22 is preferably journaled independently of the cutter spindle 2| so as to be relativelyadjustable vertically for accurately controlling the depth of the out made by the cutter (see Fig. 6). The frame H! has a depending bearing block l8.l shaped to support-the bearing 2|.l for the end of the spindle 2 I and part of this block I8.l is hollowed to form a housing for the roller 22 and a vertical slideway 22.| for the forked bearing block 22.2 in which the roller 22 is journaled on roller bearings 22.3. The block 22.2'is yieldably supported in its guideway by tension springs not shown. I

A second guide roller 24 (Fig. 1) is journaled on the elevator block 6 and rests on and is guided handle 33 which is held in its released position by a stop pin 34.

The motor frame [8 is adjustable along the guideway l6 by means of a threaded sha-ft 35 operated by a crank 36. During swanf cutting operations, the cutter I '9 is controlled by the rollers 22 and 24 and their templates 23 and 25. In

order to standardize the problems of designing .thetemplates forswar-fing operations, it is wdesirableto have the lowestpoint of the tread of roller 22 in the same horizontal plane with the bottom line .of the cutter [9 when the parts are in the position of Fig. lat which the level out is made by the cutter; Normally this plane is radial to the axis P of the bearing l2 of the tilting frame l8, but as the cutter is reduced indiameter whenever it is sharpened, it is necessary to adjust the roller 22 to correspond. This is .accomplishe.d by theooncentric set screws 31'! and- T18 '(Fig. .6-). The head 31.! .on screw 3;! bears on the bearin block 22.2 of roller 22. Set screw '33 is tubular, being internally threaded to fit set screw 31, andis externally threaded to lit a vertical bore in the frame l8. When the head 31-] is iniirmeontact with the -;lower end of set screw .38 his screw is adjusted to bring the low point p ro er 22 in line with the bottom of the cutter t9. This'adjustment remains fixed for all work that is glgine in a single operation, but when heavy cuts are made requirin r peate oper tions of th cutt the d pt f ac .su ess ic gu :is .Ghht QllQ by h s t sc w 3, wh h 1 fifll$ t e iqllle 22 to raise the cutter to the level of the first rou h ,cut .and i then backed Qfi f 99 sive .cuts until the hea 3 Q QHEA E th we e d of s t screw 8 f r the flhish hg .91 Th lo h ti -J ma he u e t leeh th i-eere 1. 1 and 8 ai st IQlh il -P29 fin fil Theinsiieete point r 1-383 had 8 s th e e a e hew .ih ihe eeh e ef e #12 seeset r m Ei e h. th e tter hih The t readed here t at ree l e set W eiilh lon ud al -seem? the set screw av be locke 3 53 Sh w i a adius ed rest qh lh ahe t -i' cla p l g? 3 1.

.In the. articular :fe ih th ee ahso ar d s o itio of l he @31 .e the e e fi t nds u on th urnin i t is i er 1 about t p vot J1 an -is iheh a ee to" th steam hr t osition o t eh hte 139 wi h i' e e t ifi escelefiflr la io o th nt heto o th 9 ments of the elevator block and tilting sector i under the control of the guide rollers'and template har i di a d dia ammat a in Fi T e-cente pf theh r 1: ieinsiihfihihfi by the numeral Poth mac ine-sho n the hea o th p vot J12 l e i th ze t p an tha tan en to he pe phe si j t cutter, the elevator guide roller 25 andthe spheri- 7 Ball uide vlioller 22 ;at the lowest pointsthereof when the motor .shai horiz ntal. This plane .of reference indicated by a broken llne in l' 'ig.

4. 1 and by the horizontal line through the point P0 in Fig. 4.

In the device shown, the position of the cutter in relation to the work is determined by two factors; a vertical movement of the pivot point P0 due to the rising and falling of the plane roller 24 as it travels along the template bar 25 andthe pivotal movement 91 the motor and its associated mechanism about the pivot point P0 due to the changes in elevation of the spherical roller 22 as determined by the template bar 23.

The cutter can be made to tilt about a selected point between its ends by changing the heights of the template bars 23 and 25, according to certain formulas. Assume, for example, that the vertical center line of the spherical roller is spaced 30 inches from the pivot P0. This distance remains constant. 4

Now, if we choose a point on the cutter that is midway between the point P0 and the vertical center line of the spherical roller, then in order to keep the point A at constant level while varying the angle of the cut made by the cutter, the elevator template bar 25 has to increase in height 7 as the tilting template bar 23 decreases in {height by a like amount in order to keep the cutter edge passing through the point AI If the pivoting of the cutter is about anyotherpointB on the cutter surface, the variation 'in" heights of the two template bars would be -infthe proportion that the distance of this .newpoint 13' from the pivot Po bears t'o' -tli' horizontal distance between point B and point C at the vertical lcenter line i of the spherical rollii Thisre latio'n is illustrated graphically in i f romwhich itI'will beseen that to tilt the cutter a ou n A i 'the el e I? .hiev e' p through angle a, the pivot P is moved downja distance d1 topoint }P1,1wlii1e 'ller 24 is'moved upward a distance 013; This-resin, accomplished by lowering the template surface 25 by an amount e u o stance @Id an by i fe' ie j p surface 23' ,by anamo in't equal 'to' distance ,ds. The p t .Pfand the r ll r 3.4 so in and 2th hlehs ra v rii e P th Whi wer 2? o e up o down on a s i ht ,eu' ved ve iha Path lt h-hu dis eehieiremih pivot P. 'In'. ath la f o'r ealc latdistance 13 t Lei ro le 2.? ,reahhe t levvenee lm d e e esie h h she sits/distance its in Fi g'f5 whicheoualspne-halfof th .s em 0J ro le 2.? times o jh i qe'ii o in ef wh t l To illustrate, let it be ass l n of the s herica lie-H pivot P0. This distance (P6 to (3) remains constant. F 3or .a zero (9 degree angle this pivot s leve w h the lewer ,ed'sie 'e the P i ro ler, spherical roller and the cutter. glhoosir g 'a refer ence m0 A at .1 1. 5 91 14519.? .195 .2 353 t and-designate h re are hi .ah ih thi reference point A at a variable angle with the ed that the center euher de hem ter sh i' eeihe'iiewh a the c r age fi av QrW-hr iheh' t eate templat bar 25 has to increase in height and the inner te p at a 2. ha t ,deereee in he ht by a likeamount to keep the cutter edge going through o ma enta-tile ratios corresponding to the ratio established by the location of the reference point A or B as the center about which the angle of the cut is to be varied.

The shaping of the templates at any position of the carriage can be calculated according to the following formulas, where Distance P to C=30 inches, Distance P0 to A=15 inches and Distance P0 to 3:20 inches. Diameter of roller 22:8 inches.

Example I.C'utter end of motor shaftgoing up Point A in cutter edge to remain at same location:

Then,

d1=15 tangent of angle a da=30 sine of angle a4 (1-cosine of a)- l5 tangent of angle a.

Point B in cutter edge to remain at same location:

d1=20 tangent of angle a d3=30 sine of angle a-4 (l-cosine of a) 20 tangent of angle a.

Example II .--C'utter end of motor shaft going down Point A in cutter edge to remain at same location:

d2=15 tangent of angle b d4=30 sine of b+4 (1cosine of b) 15 tangent of b.

It will be understood that if a pointsuch as A or B on the cutter remains in the same location, then the travel of the carriage will cause that point of the cutter to travel in a straight level line. To cut a constant angle, the motor shaft can be set and locked at that angle manually and then either template will control changes in the height of the out.

Although but one specific embodiment of this invention is herein shown and described, it will be understood that numerous details of the structure shown may be altered or omitted without departing from the spirit of the invention as defined by the following claims:

We claim:

1. In a milling machine, a work supporting elongated bed and a cutting tool mounting overlaying said bed for relative travel lengthwise of the bed; said tool mounting comprising a vertically movable elevator member, a tilting member extending transversely across said bed and turnable on said elevator member about a horizontal axis directed along said bed, and located adjacent one side of said bed and a motor-driven tool spindle journaled on said tilting member crosswise of said bed; a cutting tool on said spindle and spaced from said axis; a pair of guide rollers located respectively on said elevator member and on said tilting member; and a pair of template bars extending along said bed and respectively co-acting with said guide rollers to control respectively the elevation and tilting of said tool spindle with respect to said bed, said tilting mem ber roller being adjustable vertically relative to the axis of said spindle.

2. In a milling machine, a work supporting elongated bed and a cutting tool mounting overlaying said bed for relative travel lengthwise of the bed; said tool mounting comprising a vertically movable elevator member, a tilting member extending transversely across said bed and turnable on said elevator member about a horizontal axis directed along said bed and located at one side of said bed; a slide member movable across the bed on said tilting member; a motordriven tool spindle journaled on said. slide member crosswise of said bed; a cutting tool on said spindle and spaced from said axis; a pair of guide rollers located respectively on said elevator member adjacent the transversely extending end thereof and on said tilting member; and a pair of template bars extending along said bed and respectively coasting with said guide rollers to control respectively the elevation and tilting of said tool spindle with respect to said bed.

3. In a milling machine, a worl: supporting elongated bed and-a cutting tool mounting overlaying said bed for relative travel lengthwise of the bed; said tool mounting comprising an upright frame, an elevator member, a set of equal parallel links each having its oppositeends pivoted on said frame and elevator member respectively for vertical parallel motion control of said elevator member; a tilting member turnable on said elevator member about a horizontal axis directed along said bed and located at one side of saidbed; a motor-driven tool spindle journaled on said tilting member crosswise of said bed; a cutting tool on said spindle and spaced from said axis; a pair ofguide rollers located respectively on said elevator member and said tilting member; and a pair of template bars extending along said bed and respectively coacting with said guide rollers to control respectively the elevation of said elevator member and the tilting of said tool spindle With respect to said bed.

4. In a milling machine, an elongated work bed, a carriage'mounted above for lengthwise travel along said bed, a cutter spindle having its axis of rotation in a vertical plane transverse to the path of said carriage, a cutter on said spindle, a bearing supporting said spindle for tilting it about an axis extending along the path of travel of said carriage at one side of said cutter, means comprising horizontally directed parallel motion links having their opposite ends pivoted respectively to said bearing and carriage for vertical bodily movement of said spindle, and template means controlling the relative tilting and bodily movements of said spindle during the travel of said carriage along said bed.

5. In a milling machine, an elongated work bed, a carriage mounted above for lengthwise travel along said bed, a cutter spindle having its axis of rotation in a vertical plane transverse to the path of said carriage, a cutter on said spindle, a bearing supporting said spindle for tilting it about an axis extending along the path of travel of said carriage at one side or" said cutter, means comprising horizontally directed parallel motion links having their opposite ends pivoted respectively to said bearing and carriage for vertical bodily movement of said spindle, and template means controlling the relative tilting and bodily movements of said spindle during the travel of said carriage along said bed, said template means comprising a spherical roller journaled concentrically with said spindle and a track surface therefor on said bed. a

6. In a milling machine, an elongated work bed, a carriage mounted above for lengthwise travel along said bed, a cutter spindle having its axis of rotation in a vertical plane transverse to the path of said carriage, a cutter on said spindle,

sing a spherical .roller journaled concenally with said spindle, a second roller meeting with said parallel motion linkage to support -.said'bearing, a-nd individual track surfaces on said bed eoaoting with said rollers respectively.

7. In a milling machine, an elongated horizontal work bed, a carriage :mounted above for lengthwise travel along-saidbed, an elevator plate disposed in a vertical plane in front of said car-- riage and transverse to said bed, links connecting said elevator plate to said carriage for parallel vertical motion of said elevator plate, a .tilting :member mounted for rotation on said elevator plate about an axis disposed lengthwise of the bed adjacent one side thereof a slideWa-y on said tilting member extending crosswise of said bed, a cutter spindle bearing iframe carried by said slideway, a utter spindle journaled in said spindle bearing member on an axis extending crosswise of said bed, a roller positioned to support said elevator plate, a roller on said cutter spindleirame adjacent the .side of said bed opposite to the axis of said tilting member and controlling the angular position of said tilting membar, a cutter on said spindle between said lastnamed roller and the axis :of said tilting member, and individual template tracks along said bed respectively coacting with said rollers to control the elevation and tilting of said cutter spindle.

8. In a milling machine, a work supporting elongated bed and ,a cutting tool mounting overlaying said had for relative travel lengthwise of 8 the bed; said tool mounting oomprising a vertically vmovable elevator member, a tilting :member turnable on said elevator :member about a horizontal axis directed along said bed, a motordrlvcn tool spindle journaled on .said tilting member crosswise of said bed; a pair of guide rollers located respectively on said elevator member and said tilting member; a pair of template bars extending along said bed and respectively coacting with said guidei'ollers to control respectively the elevation and tilting of said toolspindle with respect to said bed, a bearing block on said tilting member for carrying the respective guide roller and being vertically shiftable relative to the cutter spindle, adjustable stop means on said tilting member coacting with said bearing block, said stop means comprising a tubular set screw for regulating the normal cutting position of said spindle, and a second set screw extending longitudinally through said tubular .set screw to adjust said roller bearing block for preliminary rough cuts by the tool without disturbing the adjustment of said tubular set screw.

WILLEM GRO'EN. RUDOLPHF. ONSRU-D.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,691,898 Kosfeld Nov. 13, 1928 1,985,753 Weiss Dec. 25, 1934 2,006,121 Tham' June 25, 1935 2,026,042 I -Iowe .Dec. 31, 1935 2,335,625 'Wilson Nov. 39, 1943 2,341,194 Schwartz Feb. 8, 1944 2,356,571 Dewoitine Aug. 22, 1944

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